As media becomes more user-specific in nature, the granularity with which advertising is supplied must keep pace. Some activities, like browsing the internet and playing video games, can be highly individualistic. Therefore, vendors would like to target their advertising to those users that create the best return on that advertising. This can be seen most when vendors pay for advertisements on a per-placement or a per-view basis. However, the information that is available to both the advertising provider and the vendor could further refine this narrowing of audience. On the other hand, the production of every possible advertisement the vendor could produce becomes unwieldy when there are large number of potential ads. Instead, if ads could be customized at run-time using this information, then more specific ads could be placed without the need for countless variations on the base advertisement. If customization of this nature could originate from the vendor rather than the intermediary advertising provider, another level of flexibility also could be achieved.